Frugel-Horn Mk3 Builds & Build Questions

[Plott]

Thank you all!
For the rear chamber there was an instruction, that the quantities must be the same along the entire length but it means, that the density must be increased towards the bottom. Is that right?

Best regards
Istvan

 

[Plott]

Hello,
just for fun (hmmpff... not really), a comparison... the big bags were in the front chambers vs. required amounts...
Istvan

 

[Quattrofish]

HA!

I had a similar experience when I built a pair of Dave's big MTMs. Turns out that when he says you need to really tease out the fluff, he means it!

 

[planet10]

Yes the rear point has increasing density of damping as you approach the point.

dave

 

[Plott]

Thank you Dave!
In the meantime I teased the required amount to snowflakes and I really took more than an hour

 

[chrisb]

Thank you, Chris!
The chamfering seems now to be a requirement... so now I have a lot to do but as I wrote, my first diy-speaker ever.
What was the reason of the short relationship with the MS?

Istvan

It was basically a short term listening session at home to compare a prototype build of Scott’s MLTL design for 11MS to my daily drivers (A10.3 Pensil). That was approx 3 yrs ago, and as best as I can recall, it wasn’t a night and day difference.

I had already slimmed down my stable of speakers to only those in active use - much harder than it sounds when you have emotional attached and blood, sweat, tears and treasure invested in the builds.

I’ve since retired from active building; if circumstances permitted, I’d love to play with most recent MA drivers as well as others; but after 50yrs my audioFOMO has slowly evaporated like a mid September morning dew.

 

[Plott]

Thank you, Chris, "it wasn’t a night and day" is a good info for me.
The Pluvia 7HD Gen2 are now here, so I could start with the reassembly. Concerning the wiring, I took van den Hul speaker cable, and this is not a thin one, about 12 gauge. Is it okay or should I replace it?

 

[Plott]

Hello,
now the speakers are assembled and the break-is running.
But I can tell even at such low volume, there is no sharpness, it's not shrill. However, maybe somewhat "boring". Will see, how it works after 100 hours.

 

[chrisb]

Thank you, Chris, "it wasn’t a night and day" is a good info for me.
The Pluvia 7HD Gen2 are now here, so I could start with the reassembly. Concerning the wiring, I took van den Hul speaker cable, and this is not a thin one, about 12 gauge. Is it okay or should I replace it?

AFAIC, the biggest issue with speaker wire of that gauge is terminating / connecting to drivers’ terminal tabs. I always prefer solder to crimps, and never used heavier than #18 on any of the MAs, but that’s just me, and I don’t wanna open that can of worms.

 

[planet10]

12g will be very difficult to solder.

I typically used a pair od single solid 24g strands on the inside. Yert easy to solder.

Sounds good too.’

dave

 

[Plott]

Thank you Chris and Dave.
If it is only about the soldering, so there were no issues.

 

[chrisb]

IMO, the wire inside enclosures like these for full-range drivers with relatively modest power handling just doesn’t need to be anywhere near that thick.

 

[AllenB]

Yes, as Nelson Pass documented series resistance feeding a full range driver tends to take it in a good direction.

Not that the amount of resistance isn't important, but comparing this with having a crossover in the lower treble which may put emphasis in a place where it is unwanted.

 

[Plott]

Thank you both!
"Doesn't need to be thick" means to mee it is not a failure
But maybe I will replace them during the finishing of the boxes, while the binding posts are removed.

 

[Plott]

Hello again,
15 hours of break-in of the P7.2HD and counting...
But yesterday I had to make some light modification. Contrary to the assumption the size of the Alpair 7MS and of the P7.2HD is very slightly different. The difference is 0.3 mm (0.0118 in), the P7.2HD is bigger. My cutout for the Alpair was very exact and I noticed the problem only yesterday - the P7.2HD could not be sunk in the cutout. I slightly opened up the cutout with my Proxxon mini grinding tool, just one full turn in the cutout, and now the driver can sit properly in it. I tightened the screws only very slightly as Dave wrote, and then I turned the system on... and here is it: the harshness is back, it is slightly shrill again in the higher mids
I of course applied the rubber sealing under the driver into the cutout, but I read somewhere, that it shouldn't be used necessarily. What is the truth? Until the driver wasn’t in the cutout fully, it wasn't shrill. And now it is, to some extent I hope the next 85 hours would help to improve the driver.

 

[vinylkid58]

I wonder it you're tightening the mounting screws too much, and putting stress on the driver basket? The screws should only be tight enough to slightly compress the gasket, maybe .5mm.

jeff

 

[Plott]

Jeff, the screws are tightened very slightly. But tomorrow I will loosen them up further (now it is bed-time here). The problem is that the screws must be turned into the ply which has a good portion of mechanical resistance, so I don't know where is the point where a screw begins to press the gasket.

 

[vinylkid58]

Just put your finger across the gap between the driver frame and front baffle. When the driver frame starts to be drawn in by the screws, you will be able to feel it move inwards.

Hope you have a good night.

jeff

 

[Plott]

Thank you, I will try this way

 

[Plott]

Is it really so simple? Now I tightened the screws to the point where the driver frame begins to move and then just very slightly back - and the sharpness seems to be gone. Great simple trick with the finger on it - sometimes I tend to think complicate